Remove generated directories with 100s of files.

client/dom/generated/src/wrapping/_HTMLTrackElementWrappingImplementation.dart

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-// WARNING: Do not edit - generated code.
-
-class _HTMLTrackElementWrappingImplementation extends _HTMLElementWrappingImplementation implements HTMLTrackElement {
-  _HTMLTrackElementWrappingImplementation() : super() {}
-
-  static create__HTMLTrackElementWrappingImplementation() native {
-    return new _HTMLTrackElementWrappingImplementation();
-  }
-
-  bool get isDefault() { return _get_isDefault(this); }
-  static bool _get_isDefault(var _this) native;
-
-  void set isDefault(bool value) { _set_isDefault(this, value); }
-  static void _set_isDefault(var _this, bool value) native;
-
-  String get kind() { return _get_kind(this); }
-  static String _get_kind(var _this) native;
-
-  void set kind(String value) { _set_kind(this, value); }
-  static void _set_kind(var _this, String value) native;
-
-  String get label() { return _get_label(this); }
-  static String _get_label(var _this) native;
-
-  void set label(String value) { _set_label(this, value); }
-  static void _set_label(var _this, String value) native;
-
-  int get readyState() { return _get_readyState(this); }
-  static int _get_readyState(var _this) native;
-
-  String get src() { return _get_src(this); }
-  static String _get_src(var _this) native;
-
-  void set src(String value) { _set_src(this, value); }
-  static void _set_src(var _this, String value) native;
-
-  String get srclang() { return _get_srclang(this); }
-  static String _get_srclang(var _this) native;
-
-  void set srclang(String value) { _set_srclang(this, value); }
-  static void _set_srclang(var _this, String value) native;
-
-  TextTrack get track() { return _get_track(this); }
-  static TextTrack _get_track(var _this) native;
-
-  String get typeName() { return "HTMLTrackElement"; }
-}